Police arrested a man in his 20s in connection with the strangling of a 7-year-old girl whose body was left on train tracks in the city of Niigata a week ago, investigators said Monday.

The man, who was only described as a corporate employee, has begun to confess his involvement in the death of Tamaki Omomo, a student in the second grade at Kobari Elementary School who vanished while on her way home on May 7, the investigators said.

Questioning began earlier in the day on a voluntary basis.